Liquid biopsies have been a long time coming. After more than two decades of research, the first of these blood tests — which can reveal the presence of cancer-causing genetic mutations the way a tissue sample can — has finally been approved for helping physicians make treatment decisions for cancer patients.
But the bigger ambition for these tests, being pursued by several dozen companies, is using them to screen people and detect cancer early — before it spreads — by analyzing bits of DNA and other molecules shed by tumor cells.
Some of the companies rely on identifying mutations, while others look for epigenetic markers. Still others look for protein markers that are telltale signs of cancer. And many are using artificial intelligence to help make sense of the different characteristics and how they relate to cancer.